I have had this happen a few times now and am unsure of its cause, but I think it must be related to a particular gene. It does not affect growth or anything else and does not require any "correcting", it is just a strange genetic quirk associated with some strains. Your plant "knows" what it is doing, so there is nothing to be done, other than to look at it and wonder why this occurs. There is no need to worry that something is "wrong".
Hope this helps, Organoman.